Legionella, Pseudomonas and general pathogen control in water systems Dr Tom Makin Makin & Makin Consultancy Ltd info@makinandmakin.co.uk Formerly, Directorate Manager Department of Medical Microbiology Royal Liverpool University Hospitals
Roman public latrine at Ostia
Waterborne pathogens Viruses Protozoa Fungi Bacteria
Viruses Hepatitis A Enteroviruses (polio) Rotavirus Norovirus Rotavirus Magn. x 200,000
Laboratory reports of norovirus in England and Wales 2000 to 2008(week 3) Weekly data Data from HPA
Each bather introduces 600,000 microorganisms!!
Mycobacteria M. avium complex, M. ulcerans
WHO publication
Cryptosporidium oocyst Resists 50ppm chlorine
Salmonella bacterium Bacteria Salmonella Vibrio cholera Campylobacter E. coli Pseudomonads Mycobacteria Legionella
Burkholderia cepacia, Acinetobacter spp Stenotrophomonas maltophilia
Aeromonas hydrophila, found in fresh and brackish water - rare cause of necrotising fasciitis
Necrotising fasciitis
27 th September 2012 Serratia marcescens ubiquitous. - commonly found in soil, water, plants and animals. It is widely present in non potable water. Produces red colonies Grows on bread and communion wafers possible explanation for transubstantiation miracles. Pathogenicity established in late 1950 s following US Government Operation Sea Spray re. transmission of biological weapons off coast of San Francisco increase in UTI and pneumonia cases October 2012
Pseudomonas aeruginosa
Legionella pneumophila
An Edinburgh distillery, one of the possible sources of the Legionnaires disease outbreak
Adiabatic cooler Hybrid cooler
Biofilm
There are strong selection pressures in the natural aquatic environment for the expression of virulence genes in L. pneumophila sgp 1
L. pneumophila serogroup 1, Mab 3/1 +ve (Pontiac) - causes 92% of all culture +ve cases of LD, but represents just 8% of environmental legionella Knowing which strain of legionella is in a water system is as important as the quantity of legionella present
L. pneumophila and >50 other Legionella sp. L. pneumophila causes 90% of legionellosis 16 serogroups of L. pneumophila L. pneumophila serogroup 1 cause 84% of legionellosis (Mab x9, SBT, RFLP, PFGE)
Environmenal pre-requisites for Legionella infection Temperature between 20 O C and 45 O C + Water stasis + Nutrients organic matter/biofilm/iron/amoebae Increased No s of Legionella bacteria & virulence + Aerosol generation + Susceptible host Legionnaires disease Pontiac fever
Legionnaires disease Pontiac Fever - High attack rate - 95%, inc kids Legionnaires disease - Low attack rate (1%) Stafford Hospital outbreak attack rate 5%
Legionnaires disease Rare infection 8 cases per million capita per annum in UK Approx 400 cases reported per annum in UK 2-3% of all community acquired pneumonias (CAP s) 14-37% of severe CAPs (mortality 5 to 30%)
Legionnaires disease Route of infection Inhalation of aerosols most likely (also aspiration) No evidence of person to person spread Legionella survive 2hrs in aerosols at relative humidity of 65% Aerosols created by water impacting surfaces Aerosols <5µ can enter alveoli
Admission Day 4
+1 year +7 years
HPA data 1980-2004 Legionnaires disease in the UK Incidence Mortality Travel 48% 11% (43% abroad, 5% UK) Community 46% 12% Nosocomial 6% * 32% *Exemplary water management in healthcare premises, or poor diagnosis of nosocomial cases?
Urinary antigen test has replaced antibody testing and culture for diagnosis and has contributed to a significantly reduced mortality rate for Legionnaires disease (Predominantly detects Pontiac strains of L. pneumophila sgp 1)
Data from European Centre for Disease Prevention and Control
Predominantly detects Pontiac strains of L. pneumophila sgp 1 Sensitivity for: travel 90%, non-travel 66%, nosocomial 46% (S. Jespersen et al. Scandinavian Journal of Infectious Diseases. 2009 Vol 41, p425-432)
Sources of waterborne infections Showers Taps Cooling towers Spa baths Ice machines Bottled water dispensers Humidifiers in neonatal units Ornamental fountains Flushing toilets Hydrotherapy pools and birthing pools Dental units
Sunderland Health Club 2006-2 cases of LD >120 cases of PF
Spa/Hydrotherapy pools Biannual reviews of pool water management Pool manager Pool engineer Microbiologist Therapist Water treatment company
HSE Guidance - control of legionella 1987 - EH48 1992 - ACoP + HS(G)70 1995 - HS(G)70 (revised) 1998 - H&CWS (supplement) 2001 - ACoP & Guidance (L8)?? Next version Better explanation required re. RP and DH duties Extent of reasonably practicable Accreditation, and quality of RA s Cooling tower packs
Supplementary guidance to HSE s L8 on HSE website Removal of cooling tower packs In-situ cleaning Additional measures - Side stream filtration Additional monitoring Endoscope analysis
Sources of waterborne infections Showers Taps Cooling towers Spa baths Ice machines Bottled water dispensers Humidifiers in neonatal units Ornamental fountains Flushing toilets Hydrotherapy pools and birthing pools Dental units
Sources of waterborne infections Showers Taps Cooling towers Spa baths Ice machines Bottled water dispensers Humidifiers in neonatal units Ornamental fountains Flushing toilets Hydrotherapy pools and birthing pools Dental units
Restaurant fountain Rapid City, South Dakota - 18 cases
Sources of waterborne infections Showers Taps Cooling towers Spa baths Ice machines Bottled water dispensers Humidifiers in neonatal units Ornamental fountains Flushing toilets Hydrotherapy pools and birthing pools Dental units
Lancet : February 18 th 2012; Vol 379: p684
Water stagnation
Intelligent hands-free systems Assist in preventing cross infection Auto flush facility Thermal disinfection
Electronmicrographs of EPDM
Sustainable development Solar heating system
Heat gain due to close proximity of hot and cold water supplies
Radiant heat panels
The design of the Venturi splitter to prevent water stagnation? Shorter periods of flushing, better distribution of biocides where used
Broadgreen Hospital, Liverpool Achieved control of Legionella and Pseudomonas aeruginosa St Mary s Hospital, Manchester
Hot and Cold Water Systems Controlling the risk of legionellosis High and low temperatures Chlorine Chlorine dioxide Copper and silver ions Silver and hydrogen peroxide Regular flushing of outlets Self-purging showers UV irradiation and filters Point of use filtration
Cardio-Thoracic Centre at Broadgreen Hospital, Liverpool, UK
Hot and Cold Water Systems Controlling the risk of legionellosis High and low temperatures Chlorine Chlorine dioxide Copper and silver ions Silver and hydrogen peroxide Regular flushing of outlets Self-purging showers UV irradiation and filters Point of use filtration? Sustainable development
Hot and Cold Water Systems Controlling the risk of legionellosis Point of use filtration
WHO Legionella guidelines 2007 Elderly, smokers, alcoholics Target level <1000cfu/l L. pneumophila Alert level 1000 cfu/l L. pneumophila Max level 10,000 cfu/l L. pneumophila High risk patients Severe immunodepression, transplantation, corticotherapy = 0.5mg/kg per day prednisilone for 30 days or more, or 5mg/kg/day for 5 days or more Target level not detectable (?POU filters) Alert level 250 cfu/l Legionella spp *
Athletes Village London Olympics 2012
Olympic Games 2012
Swan neck and downward displacement taps RADA Unatherm-3LL& 3HL
Downward displacement v Swan neck taps 8 month study Test rig under construction